如何在Django中将参数传递给基于类的视图？

我有一个基于类的视图，它显示登录表单。问题是我无法显示错误消息。我试图在URL的参数中发送错误消息，以在HTML模板文件中显示该错误消息。但这是行不通的。

到目前为止，这是我的代码：

表格

# a class which act as a view - it displays the login-form
class LoginForm(AuthenticationForm, BaseLoginView):
    username=forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))
    password=forms.CharField(widget=forms.PasswordInput(attrs={'class':'form-control'}))

    def get_context_data(self, **kwargs):
        context = super(LoginForm, self).get_context_data(**kwargs)
        context['error'] = ''
        return context

urls.py

urlpatterns = [
    path('login/', views_auth.LoginView.as_view(form_class=LoginForm, redirect_authenticated_user=True), name='login'), # login-page
]

views.py

# login functionality for the user
def custom_user_login(request):
    if request.method == 'GET':
        error_message = ''
        return redirect('home')

    elif request.method == 'POST':
        username = request.POST.get('username')
        password = request.POST.get('password')
        error_message = ''        

        # if the username & password is correct
        user = authenticate(request, username=username, password=password)
        if user is not None:

            # Redirecting to the required login according to user type (admin / regular-user)
            if user.is_superuser or user.is_staff:
                login(request, user)
                return redirect('admin_section/')
            else:
                login(request, user)
                return redirect('/') 

        # display error message
        else:
            base_url = reverse('login')  # /login/
            query_string =  urlencode({'error': 'The username & password combination are incorrect - please try again!'})  # error=The username & password combination are incorrect - please try again!
            url = '{}?{}'.format(base_url, query_string) # /login/?error=The username & password combination are incorrect - please try again!
            return redirect(url)  # redirects to the login page with an error-message

login.html

<!-- error message -->
<div id="error" class="alert alert-danger alert-dismissible" role="alert">
    <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
    {{ view.error }}
</div> 





<form method="post" action="{% url 'custom_login' %}">
  {% csrf_token %}

  {% for field in form %}

  <div class="form-group row">
     {{ field.errors }}
     <label for="{{ field.name }}" class="col-md-4 col-form-label text-md-right">{{ field.label }}</label>
     <div class="col-md-6">
        {{ field }}
     </div>
  </div>  

  {% endfor %}

  <div class="col-md-6 offset-md-4">
      <button type="submit" class="btn btn-primary">
         Login
      </button>
  </div>                                          
</form>